CN117367702A - High-load desorption pipeline fault diagnosis method, device and medium - Google Patents
High-load desorption pipeline fault diagnosis method, device and medium Download PDFInfo
- Publication number
- CN117367702A CN117367702A CN202311100324.8A CN202311100324A CN117367702A CN 117367702 A CN117367702 A CN 117367702A CN 202311100324 A CN202311100324 A CN 202311100324A CN 117367702 A CN117367702 A CN 117367702A
- Authority
- CN
- China
- Prior art keywords
- load desorption
- load
- diagnosis
- desorption pipeline
- pipeline
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000003795 desorption Methods 0.000 title claims abstract description 156
- 238000003745 diagnosis Methods 0.000 title claims abstract description 111
- 238000000034 method Methods 0.000 title claims abstract description 31
- 230000008859 change Effects 0.000 claims abstract description 73
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 40
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 40
- 241000156302 Porcine hemagglutinating encephalomyelitis virus Species 0.000 claims description 11
- 230000004913 activation Effects 0.000 claims description 7
- 238000004364 calculation method Methods 0.000 claims description 4
- 238000010926 purge Methods 0.000 claims description 4
- 238000001704 evaporation Methods 0.000 abstract description 4
- 230000008020 evaporation Effects 0.000 abstract description 4
- 238000012544 monitoring process Methods 0.000 description 11
- 238000010586 diagram Methods 0.000 description 9
- 238000004088 simulation Methods 0.000 description 9
- 230000003213 activating effect Effects 0.000 description 6
- 230000008901 benefit Effects 0.000 description 5
- 238000011010 flushing procedure Methods 0.000 description 4
- 239000003610 charcoal Substances 0.000 description 3
- 239000000356 contaminant Substances 0.000 description 3
- 239000003344 environmental pollutant Substances 0.000 description 2
- 229930195733 hydrocarbon Natural products 0.000 description 2
- 150000002430 hydrocarbons Chemical class 0.000 description 2
- 231100000719 pollutant Toxicity 0.000 description 2
- 238000010248 power generation Methods 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 239000002828 fuel tank Substances 0.000 description 1
- 239000003502 gasoline Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000029058 respiratory gaseous exchange Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 230000001960 triggered effect Effects 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
- 238000009834 vaporization Methods 0.000 description 1
- 230000008016 vaporization Effects 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M25/00—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture
- F02M25/08—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture adding fuel vapours drawn from engine fuel reservoir
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M15/00—Testing of engines
- G01M15/04—Testing internal-combustion engines
- G01M15/09—Testing internal-combustion engines by monitoring pressure in fluid ducts, e.g. in lubrication or cooling parts
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M3/00—Investigating fluid-tightness of structures
- G01M3/02—Investigating fluid-tightness of structures by using fluid or vacuum
- G01M3/26—Investigating fluid-tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors
- G01M3/28—Investigating fluid-tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for pipes, cables or tubes; for pipe joints or seals; for valves ; for welds
- G01M3/2807—Investigating fluid-tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for pipes, cables or tubes; for pipe joints or seals; for valves ; for welds for pipes
- G01M3/2815—Investigating fluid-tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for pipes, cables or tubes; for pipe joints or seals; for valves ; for welds for pipes using pressure measurements
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/40—Engine management systems
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Testing Of Engines (AREA)
Abstract
The invention belongs to the technical field of automobile evaporation systems, and particularly relates to a high-load desorption pipeline fault diagnosis method, a device and a medium. When the front diagnosis condition is met, the carbon tank valve is opened and closed, and the pressure change of the high-load desorption pipeline is calculated; judging whether a high-load desorption pipeline fault exists according to the pressure change of the high-load desorption pipeline; the pre-diagnostic conditions include: the supercharging diagnosis condition of the vacuum degree of the high-load desorption pipeline can be influenced; the boost diagnostic conditions include: the turbocharger causes the absolute value of the variation of the supercharging pressure of the high-load desorption pipeline to be smaller than or equal to a first threshold value. The invention takes the variation of the supercharging pressure as the condition before diagnosis, and activates the subsequent diagnosis only when the supercharging pressure fluctuates within a certain range, thereby avoiding the misjudgment caused by diagnosis under the condition of severe working condition variation. Even if the high-load desorption pipeline fails when the working condition changes severely, the pressure change is obvious, so that the fault is misjudged.
Description
Technical Field
The invention belongs to the technical field of automobile evaporation systems, and particularly relates to a high-load desorption pipeline fault diagnosis method, a device and a medium.
Background
In addition to exhaust gas emissions, automotive pollutants also include hydrocarbon vapors lost from the fuel (gasoline) system of the automobile, i.e., evaporative pollutants. This loss of hydrocarbons results from "hot dip loss" and "fuel tank breathing loss". In order to prevent evaporative contaminants from contaminating the environment, meeting regulatory evaporative emissions requirements, there is a need for an evaporative system that temporarily preserves the evaporative contaminants from escaping to the atmosphere and, when appropriate, delivers the evaporative contaminants to the engine for combustion. From the state VI, the rule mandates that the OBD system can monitor the evaporation system, specifically includes desorption flow monitoring and leakage monitoring two parts, and desorption flow monitoring includes low load pipeline desorption flow monitoring and high load pipeline desorption flow monitoring. The vaporization system is shown in fig. 1, with the canister valve CPV as a boundary, and the right (downstream) desorption line (excluding the engine intake system line) as a desorption flow diagnostic portion.
For a supercharged engine, the manifold pressure under the supercharging condition is greater than the atmospheric pressure, and at this time, desorption of the carbon canister cannot be performed. In order to meet the requirement of IV type test, the desorption capacity of the carbon tank of the whole system is improved, another desorption pipeline is needed to be added, the carbon tank can be desorbed by the pipeline under the pressurizing state, the pipeline is called a high-load desorption pipeline, such as a C pipe in fig. 1, and the pressure sensor is a high-load pipeline pressure sensor P1; p2 is the pressure at the venturi tube and is obtained through calculation; p3 is boost pressure; p4 is the pre-turbocharger pressure.
The desorption power of the high-load desorption pipeline is generally from the negative pressure generated at the downstream of the air filter or the upstream of the turbocharger during the high-load operation of the engine, and the negative pressure is not as great and stable as the negative pressure in the air inlet manifold, so that a venturi tube is usually added for fully playing the capacity of the high-load desorption pipeline, and the pressure at the venturi tube is calculated according to the pressure before and after pressurization and the characteristic curve of the venturi tube and is P2. The system arrangement of the double desorption lines is shown in figure 1.
The desorption pipeline is blocked or disconnected, so that the desorption function of the carbon tank cannot be realized, and related faults are reported. At present, for a high-load desorption pipeline (C pipe), a diagnosis function is used for diagnosing under a supercharging working condition by using a pressure sensor on the C pipe. If there is no fault, the pressure in the line will change beyond the threshold value due to the desorption gas flow entering the desorption line. If the desorption pipeline is broken and blocked and the carbon tank valve is stuck in a normally open state and a normally closed state, the pressure change in the desorption pipeline cannot exceed a threshold value.
In addition to whether the high load desorption line is blocked or disconnected, this can affect the pressure variation in the desorption line, which also depends on the vacuum level of the high load desorption line. Since the pressure fluctuations generated during the canister valve opening can only be determined when the high load desorption line is sufficiently differentiated from the ambient pressure, the key variable to activate the pressure sensor based diagnostics is the vacuum level at the canister valve. At present, the conventional diagnosis mode is as shown in fig. 2, and the influence of vacuum degree on diagnosis cannot be completely eliminated, which has the following disadvantages:
1. at present, under the conditions of high vehicle speed, supercharging working condition and quick electric quantity consumption of the vehicle types such as HEV, PHEV and the like, when a larger torque demand exists at the VCU end, the series mode is switched to the parallel mode, and the engine and the motor are driven simultaneously. After the mode is switched, the rotation speed is reduced, and the supercharging pressure is rapidly increased or the supercharging is overshot. The pressure sensor detects that the pressure drops obviously because the boost pressure rises sharply, so that the vacuum degree of the high-load pipeline also rises; at this time, if there is a stuck charcoal canister valve or a high-load pipeline blocked fault, the data change is shown in fig. 5, and when the desorption diagnosis is performed, the charcoal canister valve is suddenly fully opened, and a large pressure fluctuation is detected (the root cause of the pressure fluctuation is the sudden rise of the boost pressure), and finally the charcoal canister valve and the pipeline are erroneously identified as normal, and no fault is detected.
2. The current identification of the change of the diagnosis working condition is only identified by the throttle opening change amount, and the diagnosis activating condition is only satisfied by considering the condition that the throttle opening change amount is small. However, in the case of HEV or PHEV vehicles, the throttle opening is about 100% during high-speed running or large-throttle running, and a sudden change in throttle opening cannot be detected, and a sudden change condition in which the intake boost pressure suddenly increases cannot be recognized, so that diagnosis cannot be well suppressed.
Disclosure of Invention
The invention discloses a high-load desorption pipeline fault diagnosis method, a device and a medium, which can obviously improve the fault diagnosis accuracy of a high-load desorption pipeline.
In order to achieve the above purpose, on the one hand, a fault diagnosis method for a high-load desorption pipeline is provided, which comprises the following specific steps:
when the front diagnosis condition is met, the carbon tank valve is opened and closed, and the pressure change of the high-load desorption pipeline is calculated;
judging whether a high-load desorption pipeline fault exists according to the pressure change of the high-load desorption pipeline;
the pre-diagnostic conditions include: the supercharging diagnosis condition of the vacuum degree of the high-load desorption pipeline can be influenced;
the boost diagnostic conditions include: the turbocharger causes the absolute value of the variation of the supercharging pressure of the high-load desorption pipeline to be smaller than or equal to a first threshold value.
The embodiment has the advantages that the variation of the supercharging pressure is used as the condition before diagnosis, the subsequent diagnosis is activated only when the supercharging pressure fluctuates within a certain range, and the misjudgment caused by diagnosis under the condition of severe working condition variation is avoided. Even if the high-load desorption pipeline fails when the working condition changes severely, the pressure change is obvious, so that the fault is misjudged.
Optionally, the boost diagnostic conditions further include one or more of any of the following:
the absolute value of the engine speed variation is smaller than or equal to a second threshold value;
the absolute value of the required torque variation is smaller than or equal to a third threshold value;
the absolute value of the vacuum degree variation is equal to or smaller than the fourth threshold value.
The embodiment has the advantages that the situation of severe working condition change can be further accurately eliminated by combining the supercharging pressure variable quantity of the high-load desorption pipeline with the engine speed variable quantity, the required torque variable quantity and the vacuum degree variable quantity, and the possibility of misjudgment is further reduced.
Further, the vacuum degree calculation method comprises the following steps:
the pressure before turbocharging is subtracted from the turbocharging pressure to construct a Venturi characteristic curve;
subtracting the Venturi characteristic curve from the pressure before turbocharging to obtain the pressure at the Venturi tube;
the vacuum was calculated by subtracting the pressure difference at the venturi from the atmospheric pressure.
Further, the pre-diagnosis condition further comprises a diagnosis working condition;
the diagnostic operating conditions include: the absolute value of the vacuum degree is equal to or higher than the fifth threshold value.
The advantage of this embodiment is that satisfying the absolute value of the vacuum degree can further improve the diagnostic accuracy on the basis of satisfying the supercharging diagnostic condition.
Optionally, the diagnostic working conditions further include one or more of any of the following conditions:
canister purge flow integral, exhaust flow integral, throttle opening variation.
The embodiment has the advantages that when the vehicle runs at a high speed, the throttle valve is fully opened, the working condition vacuum degree is inferred to be higher according to the boost pressure, and the vehicle is in a high-load pipeline desorption diagnosis interval. The working condition has low electric quantity, the series power generation working condition is switched to the parallel driving, and the rotation speed is changed severely. After the switching to the parallel connection, the supercharging is slightly over-regulated, the rotating speed variation is required to be introduced as a diagnosis activating condition, the working condition variation is recognized in advance, and the diagnosis is inhibited. And when the rotation speed tends to be stable, the supercharging pressure variation and the like are introduced as diagnosis activating conditions to inhibit diagnosis.
Optionally, the pre-diagnosis condition further includes a diagnosis physical condition, and the diagnosis physical condition includes one or more of the following conditions:
engine temperature, ambient temperature, battery voltage, altitude, canister purge closed loop control activation.
Optionally, judging whether a high-load desorption pipeline fault exists or not, wherein the specific method comprises the following steps of:
if the pressure change of the high-load desorption pipeline caused by opening and closing the carbon tank valve is larger than a judging threshold value, judging that the high-load desorption pipeline has no fault;
and if the pressure change of the high-load desorption pipeline caused by opening and closing the carbon tank valve is smaller than or equal to the judging threshold value, judging that the high-load desorption pipeline has faults.
Optionally, judging whether a high-load desorption pipeline fault exists or not, wherein the specific method comprises the following steps of:
the carbon tank valve is opened and closed for a plurality of times, and the average value of the pressure change of the high-load desorption pipeline caused by opening and closing the carbon tank valve is calculated;
if the pressure change average value of the high-load desorption pipeline is larger than the judging threshold value, judging that the high-load desorption pipeline has no fault;
and if the pressure change average value of the high-load desorption pipeline is smaller than or equal to the judging threshold value, judging that the high-load desorption pipeline has faults.
Preferably, judging whether a high-load desorption pipeline fault exists or not, wherein the specific method comprises the following steps of:
the carbon tank valve is opened and closed for a plurality of times, and the pressure change of a high-load desorption pipeline caused by opening and closing the carbon tank valve each time is calculated;
if the number of times that the pressure change of the high-load desorption pipeline is larger than the judgment threshold value reaches the preset number of times, judging that the high-load desorption pipeline has no fault;
and if the frequency of the pressure change of the high-load desorption pipeline is smaller than or equal to the judgment threshold value and reaches the preset frequency, judging that the high-load desorption pipeline has faults.
Further, the method is used for diagnosing the faults of the high-load desorption pipelines of the series-parallel HEV or PHEV model under the supercharging working condition.
The embodiment has the advantages that when the vehicle types such as HEV, PHEV and the like have larger torque requirement, as shown in fig. 4, the series mode is switched to the parallel mode, when the engine and the motor are driven simultaneously, the situation that the rotation speed is reduced, the supercharging pressure is rapidly increased or the supercharging overshoot occurs, and the vacuum degree of a high-load pipeline is increased and the pressure is obviously reduced due to the rapid increase of the supercharging pressure; if the high-load pipeline faults exist at the moment, the carbon tank valve is suddenly fully opened when diagnosis is carried out, and the fault is misjudged to be undetected when the pressure fluctuation is detected to be large.
In order to achieve the above object, another aspect provides a high-load desorption line fault diagnosis device, including: the front diagnosis condition judging module and the fault diagnosis module;
the front diagnosis condition judging module judges whether the automobile to be diagnosed meets the front diagnosis condition or not, and sends a judging result to the fault diagnosis module;
the fault diagnosis module is used for controlling the carbon tank to be opened and closed if the front diagnosis condition judgment module judges that the front diagnosis condition judgment module accords with the threshold, calculating the pressure change of the high-load desorption pipeline, and judging whether the high-load desorption pipeline has faults or not according to the pressure change of the high-load desorption pipeline;
the pre-diagnosis condition judging module judges whether the automobile to be diagnosed meets the pre-diagnosis condition through whether the absolute value of the variation of the supercharging pressure of the high-load desorption pipeline caused by the turbocharger is smaller than or equal to a first threshold value.
In order to achieve the above objective, another aspect provides a storage medium storing a plurality of instructions, and a processor loads the plurality of instructions to execute the high-load desorption line fault diagnosis method.
It should be noted that, the terms "first", "second", and the like are used herein merely to describe each component in the technical solution, and do not constitute a limitation on the technical solution, and are not to be construed as indicating or implying importance of the corresponding component; elements with "first", "second" and the like mean that in the corresponding technical solution, the element includes at least one.
Drawings
In order to more clearly illustrate the technical solution of the present invention, the technical effects, technical features and objects of the present invention will be further understood, and the present invention will be described in detail below with reference to the accompanying drawings, which form a necessary part of the specification, and together with the embodiments of the present invention serve to illustrate the technical solution of the present invention, but not to limit the present invention.
Like reference numerals in the drawings denote like parts, in particular:
fig. 1 is a schematic diagram of an evaporation system in the background art.
Fig. 2 is a schematic diagram of a fault diagnosis flow of a conventional high-load desorption pipeline in the background art.
Fig. 3 is a data change schematic of the high load pipeline diagnosis process in example 2.
Fig. 4 is a schematic diagram of the powertrain of the HEV.
FIG. 5 is a schematic diagram of data change during failure and omission of a stuck carbon canister valve in the background art.
Fig. 6 is a schematic diagram of the diagnostic flow chart of example 3.
Fig. 7 is a schematic diagram showing the data change in the first simulation in example 3.
Fig. 8 is a diagram showing the data change in the second simulation in example 3.
Fig. 9 is a diagram showing the data change in the third simulation in example 3.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and examples. Of course, the following specific examples are set forth only to illustrate the technical solution of the present invention, and are not intended to limit the present invention. Furthermore, the parts expressed in the examples or drawings are merely illustrative of the relevant parts of the present invention, and not all of the present invention.
Example 1:
a fault diagnosis method for a high-load desorption pipeline comprises the following specific steps:
s1, judging whether the pre-diagnosis condition is met.
Specifically, the pre-diagnosis condition includes a supercharging diagnosis condition.
Specifically, the supercharging diagnostic conditions include: the turbocharger causes the absolute value of the variation of the supercharging pressure of the high-load desorption pipeline to be smaller than or equal to a first threshold value.
And S2, if the pressure change is met, opening and closing the carbon tank valve, and calculating the pressure change of the high-load desorption pipeline.
And S3, judging whether the high-load desorption pipeline has faults according to the pressure change of the high-load desorption pipeline.
Specifically, if the pressure change of the high-load desorption pipeline caused by opening and closing the carbon tank valve is larger than a judging threshold value, judging that the high-load desorption pipeline has no fault; and if the pressure change of the high-load desorption pipeline caused by opening and closing the carbon tank valve is smaller than or equal to the judging threshold value, judging that the high-load desorption pipeline has faults.
The pre-diagnostic conditions include: the supercharging diagnosis condition of the vacuum degree of the high-load desorption pipeline can be influenced;
the boost diagnostic conditions include: the turbocharger causes the absolute value of the variation of the supercharging pressure of the high-load desorption pipeline to be smaller than or equal to a first threshold value.
Example 2:
a fault diagnosis method for a high-load desorption pipeline comprises the following specific steps:
s1, judging whether the pre-diagnosis condition is met.
Specifically, the pre-diagnosis conditions include a supercharging diagnosis condition and a diagnosis operating condition,
specifically, the supercharging diagnostic conditions include: the turbocharger causes the absolute value of the variation of the supercharging pressure of the high-load desorption pipeline to be smaller than or equal to a first threshold value, and the absolute value of the variation of the engine speed to be smaller than or equal to a second threshold value.
The diagnosis working conditions include: the absolute value of the vacuum degree is equal to or higher than the fifth threshold value.
In this embodiment, the most critical condition is the vacuum level, and the key variable for activating the pressure sensor based diagnostics is the vacuum level at the canister valve, since the pressure fluctuations generated during canister valve opening can only be determined when they are sufficiently differentiated from the ambient pressure. High desorption diagnostics require a sufficient vacuum to be performed.
The calculation of the vacuum is pv=pu-P2, i.e. the difference between the atmospheric pressure and the pressure at the venturi. And P2 is calculated as follows:
P3-P4 is used as the abscissa value of the array P_cut, P_cut is the Venturi characteristic curve, and the pressure of the Venturi pipeline is obtained through P4-P_cut. The calibration of P_cut is based on the fact that after closing the canister valve, the pressure at the venturi is theoretically equal to the pressure measured by the high load line pressure sensor. And the carbon tank valve is closed, the engine is adjusted to run to different steady-state working conditions, and the parameter P_cut is adjusted, so that the venturi tube pressure P2 is close to the high-load pressure sensor pressure P1. When the engine is in a standby state, the desorption flow monitoring function continuously updates the reference pressure according to the actual measurement signal of the pressure sensor until the operation condition of the monitoring function is met. When the diagnosis physical conditions and working conditions are met, the carbon tank valve is in a closed state. Then, the monitoring function actively opens the canister valve for a period of time and continuously calculates the pressure change in the desorption line during this period of time, i.e., the difference between the measured pressure and the reference pressure. When no fault exists, the pressure in the pipeline can change greatly because desorption airflow enters the desorption pipeline. If the pressure change exceeds the threshold, the no fault counter is incremented by 1. After several tests, when the fault-free counter exceeds its upper limit, the monitoring of this driving cycle is completed and there is no fault. If the desorption pipeline is broken and blocked and the carbon tank valve is blocked in a normally open state and a normally closed state, the pressure change in the desorption pipeline does not exceed a threshold value, and the fault counter is increased by 1. After detection for several times, when the fault counter exceeds the upper limit, the monitoring of the driving cycle is completed, and the desorption flow monitoring function reports faults. FIG. 3 is a schematic diagram showing the data change in the diagnosis process of the high-load pipeline, if the pipeline is normal, under the condition of a certain vacuum degree, when the carbon tank valve is opened, the pressure difference dP of the pipeline is larger, and if the pipeline is blocked or disconnected, the dP is smaller.
And S2, if the pressure change is met, opening and closing the carbon tank valve, and calculating the pressure change of the high-load desorption pipeline.
And S3, judging whether the high-load desorption pipeline has faults according to the pressure change of the high-load desorption pipeline.
Specifically, the carbon tank valve is opened and closed for a plurality of times, and the average value of the pressure change of the high-load desorption pipeline caused by opening and closing the carbon tank valve is calculated; if the pressure change average value of the high-load desorption pipeline is larger than the judging threshold value, judging that the high-load desorption pipeline has no fault; and if the pressure change average value of the high-load desorption pipeline is smaller than or equal to the judging threshold value, judging that the high-load desorption pipeline has faults.
Example 3:
a fault diagnosis method for a high-load desorption pipeline is shown in fig. 6, and the specific method is as follows:
s1, judging whether the pre-diagnosis condition is met.
Specifically, the pre-diagnosis conditions include: the boost diagnostic conditions, the diagnostic operating conditions, and the diagnostic physical conditions.
Specifically, the supercharging diagnostic conditions include: the turbocharger causes the high-load desorption line to have an absolute value of the variation in the supercharging pressure of the first threshold value or less, an absolute value of the variation in the engine speed of the second threshold value or less, an absolute value of the variation in the required torque of the third threshold value or less, and an absolute value of the variation in the vacuum degree of the fourth threshold value or less.
Specifically, the diagnostic operating conditions include: the absolute value of the vacuum degree is greater than or equal to a fifth threshold, the canister flushing flow integral judgment, the exhaust flow integral judgment, and the throttle opening variation judgment.
Specifically, diagnosing physical conditions includes: engine temperature determination, ambient temperature determination, battery voltage determination, altitude determination, and canister flushing closed-loop control activation determination.
And S2, if the pressure change is met, opening and closing the carbon tank valve, and calculating the pressure change of the high-load desorption pipeline.
And S3, judging whether the high-load desorption pipeline has faults according to the pressure change of the high-load desorption pipeline.
Specifically, the carbon tank valve is opened and closed for a plurality of times, and the pressure change of a high-load desorption pipeline caused by opening and closing the carbon tank valve each time is calculated;
if the number of times that the pressure change of the high-load desorption pipeline is larger than the judgment threshold value reaches the preset number of times, judging that the high-load desorption pipeline has no fault; and if the frequency of the pressure change of the high-load desorption pipeline is smaller than or equal to the judgment threshold value and reaches the preset frequency, judging that the high-load desorption pipeline has faults.
Simulation was performed with this embodiment, and the first simulation data change is shown in fig. 7, where P3 is the boost pressure p3_lt, which is the filtered boost pressure, and a_deltap is the absolute value of the amount of boost pressure change. Only setting code bit 0=true, and a_deltap is the absolute value of the difference between the increasing pressure and the filtering value thereof, reflecting the variation of the supercharging pressure; when the conditions of the vacuum degree and other diagnosis working conditions are met, the high-load pipeline desorption diagnosis activation condition is further triggered according to the condition that the A_deltaP is smaller than the threshold value Pmax, as shown in the figure, B_dact=TRUE; the condition of severe change of working conditions is avoided for diagnosis, and the condition of missing report faults is reduced.
The simulation is performed by using the embodiment, and the second simulation data change is shown in fig. 8, wherein V is the vehicle speed, R is the load, P3 is the boost pressure, pv is the vacuum degree of the high-load pipeline, ps is the intake pressure, and S is the rotation speed. The running working condition is a high-speed running working condition, the throttle valve is fully opened, the vacuum degree of the working condition is deduced to be higher according to the supercharging pressure, and the high-load pipeline is in a desorption diagnosis interval. As can be seen from the corresponding values of the cursor 1 and the cursor 2, the engine speed and the vehicle speed are basically unchanged, the supercharging pressure P3 and the like are rapidly increased, and supercharging overshoot occurs. For this working condition, the rotational speed variation, the vehicle speed variation, and the like are selected as the diagnostic activation conditions, and obviously the expected target cannot be reached. For this condition, the amount of change in boost pressure, the amount of change in load, etc. may be selected as the diagnostic activation condition.
Simulation was performed with this embodiment, and the third simulation data change is shown in fig. 9. The running working condition is high-speed running, the throttle valve is fully opened, the working condition is inferred to have higher vacuum degree according to the supercharging pressure, and the high-load pipeline is in a desorption diagnosis interval. The working condition has low electric quantity, the series power generation working condition is switched to the parallel driving, and the rotation speed is changed severely. After switching to parallel, the boost is slightly overshot. The rotation speed variation is required to be introduced as a diagnosis activating condition, the working condition variation is recognized in advance, and the diagnosis is inhibited. And when the rotation speed tends to be stable, the supercharging pressure variation and the like are introduced as diagnosis activating conditions to inhibit diagnosis.
As is clear from step S1 of embodiment 1, embodiment 2 and embodiment 3, the pre-diagnosis condition may be any combination of the supercharging diagnosis condition, the diagnosis condition, and the diagnosis physical condition according to the implementation requirements. Other conditions that can affect the change in vacuum can of course be included.
The supercharging diagnostic condition may be any combination of supercharging pressure, engine speed variation, required torque variation, and vacuum degree variation according to the implementation requirements. Of course, the boost diagnostic conditions may be other conditions that cause a dramatic change in boost pressure to affect the fault diagnosis.
The diagnosis working condition can be any combination of absolute value of vacuum degree, carbon tank flushing flow integral, exhaust flow integral and throttle opening variable according to implementation requirements. Of course, other conditions for judging that the ambient pressure and the current high-load desorption pipeline pressure are suitable for fault diagnosis can be adopted.
The diagnosis physical conditions comprise any combination of engine temperature judgment, environment temperature judgment, battery voltage judgment, altitude judgment, carbon tank flushing closed-loop control activation judgment according to implementation requirements. Of course, other external factors that can help set the diagnostic differential pressure threshold are also possible.
From step S3 of examples 1, 2 and 3, it is known that the canister valve can be opened and closed once or a plurality of times to diagnose whether a high load desorption line failure occurs. If the carbon tank valve is opened and closed for multiple times, the fault diagnosis of the high-load desorption pipeline can be carried out by adopting a common statistical mathematical means or other means capable of increasing the data stability.
It should be noted that the foregoing examples are merely for clearly illustrating the technical solution of the present invention, and those skilled in the art will understand that the embodiments of the present invention are not limited to the foregoing, and that obvious changes, substitutions or alterations can be made based on the foregoing without departing from the scope covered by the technical solution of the present invention; other embodiments will fall within the scope of the invention without departing from the inventive concept.
Claims (12)
1. The fault diagnosis method for the high-load desorption pipeline is characterized by comprising the following steps of:
when the front diagnosis condition is met, the carbon tank valve is opened and closed, and the pressure change of the high-load desorption pipeline is calculated;
judging whether a high-load desorption pipeline fault exists according to the pressure change of the high-load desorption pipeline;
the pre-diagnostic conditions include: the supercharging diagnosis condition of the vacuum degree of the high-load desorption pipeline can be influenced;
the boost diagnostic conditions include: the turbocharger causes the absolute value of the variation of the supercharging pressure of the high-load desorption pipeline to be smaller than or equal to a first threshold value.
2. The high load desorption line fault diagnosis method as set forth in claim 1, wherein the supercharging diagnosis condition further includes one or more of the following conditions:
the absolute value of the engine speed variation is smaller than or equal to a second threshold value;
the absolute value of the required torque variation is smaller than or equal to a third threshold value;
the absolute value of the vacuum degree variation is equal to or smaller than the fourth threshold value.
3. The high-load desorption line fault diagnosis method according to claim 2, wherein the vacuum degree calculation method is as follows:
the pressure before turbocharging is subtracted from the turbocharging pressure to construct a Venturi characteristic curve;
subtracting the Venturi characteristic curve from the pressure before turbocharging to obtain the pressure at the Venturi tube;
the vacuum was calculated by subtracting the pressure difference at the venturi from the atmospheric pressure.
4. The high load desorption line fault diagnosis method as set forth in claim 1, wherein said pre-diagnosis conditions further include a diagnosis working condition;
the diagnostic operating conditions include: the absolute value of the vacuum degree is equal to or higher than the fifth threshold value.
5. The method for diagnosing a fault in a high load desorption line as claimed in claim 4, wherein said conditions for diagnosing further include any one or more of:
canister purge flow integral, exhaust flow integral, throttle opening variation.
6. The high load desorption line fault diagnosis method as set forth in claim 1, wherein the pre-diagnosis conditions further include diagnosis physical conditions including one or more of any one of the following conditions:
engine temperature, ambient temperature, battery voltage, altitude, canister purge closed loop control activation.
7. The high-load desorption line fault diagnosis method as set forth in claim 1, wherein it is judged whether there is a high-load desorption line fault, and the specific method is as follows:
if the pressure change of the high-load desorption pipeline caused by opening and closing the carbon tank valve is larger than a judging threshold value, judging that the high-load desorption pipeline has no fault;
and if the pressure change of the high-load desorption pipeline caused by opening and closing the carbon tank valve is smaller than or equal to the judging threshold value, judging that the high-load desorption pipeline has faults.
8. The high-load desorption line fault diagnosis method as set forth in claim 1, wherein it is judged whether there is a high-load desorption line fault, and the specific method is as follows:
the carbon tank valve is opened and closed for a plurality of times, and the average value of the pressure change of the high-load desorption pipeline caused by opening and closing the carbon tank valve is calculated;
if the pressure change average value of the high-load desorption pipeline is larger than the judging threshold value, judging that the high-load desorption pipeline has no fault;
and if the pressure change average value of the high-load desorption pipeline is smaller than or equal to the judging threshold value, judging that the high-load desorption pipeline has faults.
9. The high-load desorption line fault diagnosis method as set forth in claim 1, wherein it is judged whether there is a high-load desorption line fault, and the specific method is as follows:
the carbon tank valve is opened and closed for a plurality of times, and the pressure change of a high-load desorption pipeline caused by opening and closing the carbon tank valve each time is calculated;
if the number of times that the pressure change of the high-load desorption pipeline is larger than the judgment threshold value reaches the preset number of times, judging that the high-load desorption pipeline has no fault;
and if the frequency of the pressure change of the high-load desorption pipeline is smaller than or equal to the judgment threshold value and reaches the preset frequency, judging that the high-load desorption pipeline has faults.
10. The high load desorption line fault diagnosis method according to claim 1, which is used for high load desorption line fault diagnosis of series, parallel HEV or PHEV vehicle types under a supercharging condition.
11. A high load desorption line fault diagnosis device, comprising: the front diagnosis condition judging module and the fault diagnosis module;
the front diagnosis condition judging module judges whether the automobile to be diagnosed meets the front diagnosis condition or not, and sends a judging result to the fault diagnosis module;
the fault diagnosis module is used for controlling the carbon tank to be opened and closed if the front diagnosis condition judgment module judges that the front diagnosis condition judgment module accords with the threshold, calculating the pressure change of the high-load desorption pipeline, and judging whether the high-load desorption pipeline has faults or not according to the pressure change of the high-load desorption pipeline;
the pre-diagnosis condition judging module judges whether the automobile to be diagnosed meets the pre-diagnosis condition through whether the absolute value of the variation of the supercharging pressure of the high-load desorption pipeline caused by the turbocharger is smaller than or equal to a first threshold value.
12. A storage medium storing instructions for loading by a processor a method for diagnosing a high load desorption line fault according to any one of claims 1 to 10.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311100324.8A CN117367702A (en) | 2023-08-30 | 2023-08-30 | High-load desorption pipeline fault diagnosis method, device and medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311100324.8A CN117367702A (en) | 2023-08-30 | 2023-08-30 | High-load desorption pipeline fault diagnosis method, device and medium |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117367702A true CN117367702A (en) | 2024-01-09 |
Family
ID=89406698
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311100324.8A Pending CN117367702A (en) | 2023-08-30 | 2023-08-30 | High-load desorption pipeline fault diagnosis method, device and medium |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117367702A (en) |
-
2023
- 2023-08-30 CN CN202311100324.8A patent/CN117367702A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4304513B2 (en) | Abnormality diagnosis device for evaporative gas purge system | |
| US9551304B2 (en) | Tank venting system and method for diagnosing same | |
| US10815938B2 (en) | Method for diagnosing leakage of fuel vapor purge system | |
| KR101951619B1 (en) | Method for diagnosing a tank ventilation system | |
| CN113302382B (en) | Method and device for checking the functionality of a crankcase ventilation system of an internal combustion engine | |
| CN110031160A (en) | Fuel evaporation leak detection system and method | |
| US11506149B2 (en) | Leak diagnosis system using active purge pump and leak diagnosis method using active purge pump | |
| US10927794B2 (en) | Active canister purge system and diagnostic method thereof | |
| CN110361198B (en) | Vehicle evaporative emission system desorption flow fault detection device and method and vehicle | |
| US20200318563A1 (en) | Method and system for diagnosing fault of dual purge system | |
| US8365706B2 (en) | Method and device for testing the tightness of a fuel tank of an internal combustion engine | |
| CN111946476A (en) | Method and system for monitoring desorption flow of high-load desorption pipeline of evaporation system | |
| US10527008B2 (en) | Diagnostic method for diagnosing sticking of canister purge valve and automotive diagnostic system therefor | |
| US11047344B2 (en) | Leakage diagnosis supplement method for failure of vacuum pump using active purge pump and leakage diagnosis supplement system for failure of vacuum pump using active purge pump | |
| CN113417767B (en) | Positive pressure type desorption pipeline flow diagnosis method based on fuel tank leakage diagnosis module | |
| CN117367702A (en) | High-load desorption pipeline fault diagnosis method, device and medium | |
| US11187193B1 (en) | Active dual purge system and method of diagnosing active dual purge system using onboard diagnosis | |
| CN113775439A (en) | Method and system for detecting flow of low-load desorption pipeline of active intervention type evaporation system | |
| KR20220026736A (en) | System and method for diagnosis of vehicle purge line | |
| KR20210117736A (en) | Active purge system and diagnosis method for active purge system using on-board diagnosis | |
| CN115324779B (en) | Desorption diagnosis method, desorption device, storage medium, controller and vehicle | |
| CN114251199B (en) | Carbon tank desorption pipeline diagnosis method, controller and engine | |
| KR102323409B1 (en) | Method and system for diagnosing boost pressure sensor | |
| US11499494B1 (en) | Method for diagnosing fuel leakage of a vehicle | |
| CN116950812A (en) | High-load pipeline desorption flow diagnosis method, device and storage medium |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |